Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, P. R. China.
Nanoscale. 2017 Oct 26;9(41):15901-15910. doi: 10.1039/c7nr06662g.
Three-dimensional surface-enhanced Raman scattering (SERS) substrates are prepared via the in situ deposition of silver nanoparticles (AgNPs) on silica nanowire (SiO NW) assemblies, either in a free-standing membrane structure or as an optically transparent film supported on Scotch tape. The negatively charged surface of the SiO NW favors Ag ion enrichment around itself, with the ions forming densely deposited AgNPs on the NW after reducing agents are added to the solution. A SERS substrate with high sensitivity is achieved owing to abundant "hot spots" generated by the inter-AgNP gaps in the 3D geometry of the NW networks. The AgNP-deposited SiO NW membrane has a SERS enhancement factor of 2.9 × 10 and a detection limit of 10 M towards 4-mercaptopyridine probing and 10 M towards dithiocarbamate pesticide (i.e., thiram) probing. Moreover, the AgNP-deposited, Scotch tape-supported SiO NW film achieves non-invasive, direct detection of real-world surfaces due to its high sensitivity, high flexibility and optically transparent properties.
通过在二氧化硅纳米线（SiO NW）组装体上原位沉积银纳米粒子（AgNPs），可以制备三维表面增强拉曼散射（SERS）基底，无论是在独立的膜结构中，还是在 Scotch 胶带支撑的光学透明薄膜中。SiO NW 的带负电荷的表面有利于 Ag 离子在其周围富集，加入还原剂后，离子在 NW 上形成密集沉积的 AgNPs。由于 NW 网络的 3D 几何形状中 AgNP 之间的间隙产生了丰富的“热点”，因此实现了具有高灵敏度的 SERS 基底。沉积有 AgNP 的 SiO NW 膜对 4-巯基吡啶的探测具有 2.9×10 的 SERS 增强因子和 10 M 的检测限，对二硫代氨基甲酸盐农药（即福美双）的探测具有 10 M 的检测限。此外，由于沉积有 AgNP 的 Scotch 胶带支撑的 SiO NW 薄膜具有高灵敏度、高柔韧性和光学透明性，因此可以实现对真实表面的非侵入性、直接检测。
